In cooling devices as known from, for example, DE 103 58 641 A1, the embodiment of the cooler is very expensive, therefore cost intensive, and the assembly of the individual modules is complicated. Further, here the problem occurs that the cooling effect is not distributed in a uniform manner over all modules.
An alternative, that of direct cooling, has the disadvantage that a sealing of the water transferring areas in the vicinity of the electronics is required, and that the operating conditions with long operating times of the electronics and the comprehensive damage that can result from an electronics failure have meant that until now the risk of possible leakages in the state of the art devices have most frequently prevented the use of an open water cooler. The classic method with a cooling plate only permits the planar arrangement of modules and thus requires a substantially larger base than a stacked design. Further, also the module assembly is expensive here.
U.S. Pat. No. 6,542,365 B2 describes cooling hoses with elastic sections, semi-conductor devices being retained between middle and end sections of the cooling hoses. These complex structures involve increased leakage risks, as the coolant channels are often bent and exposed to mechanical influences. Due to their complexity, these devices can only be manufactured at high costs.
Finally, EP 1 815 514 B1 of the applicant should also be mentioned, which concerns a flow distribution module, whereby substrates from the power modules are arranged in hollows of the housing. Special inlet distributors and outlet distributors provide flow connections. Due to the identical geometry of the modules, they have the same flow resistance, so that at certain points different flows can occur in several modules.